In this image made from video provided by NASA, astronauts Chris Cassidy, foreground, and Tom Marshburn prepare for a possible spacewalk from the International Space Station on Friday, May 10, 2013. NASA will decide later Friday if the two astronauts will step outside the station to work on a leaking coolant line. The line chills power systems but power was rerouted and is operating normally. The six-member crew is not in danger. (AP Photo/NASA)
In this image made from video provided by NASA, astronauts Chris Cassidy, foreground, and Tom Marshburn prepare for a possible spacewalk from the International Space Station on Friday, May 10, 2013. NASA will decide later Friday if the two astronauts will step outside the station to work on a leaking coolant line. The line chills power systems but power was rerouted and is operating normally. The six-member crew is not in danger. (AP Photo/NASA)
FILE - In this Monday July 27, 2009 image provided by NASA, astronauts Tom Marshburn, left, and Christopher Cassidy participate in a spacewalk for maintenance tasks. On Friday, May 10, 2013, the two astronauts are preparing for a possible impromptu spacewalk to work on a leaking ammonia coolant line. The line chills power systems but power was rerouted and is operating normally. The six-member crew is not in danger. NASA will decide Friday evening if the spacewalk is needed on Saturday. (AP Photo/NASA)
FILE - This May 23, 2011 file photo released by NASA shows the International Space Station at an altitude of approximately 220 miles above the Earth, taken by Expedition 27 crew member Paolo Nespoli from the Soyuz TMA-20 following its undocking. NASA on Thursday, May 9, 2013 said the International Space Station has a radiator leak in its power system. The outpost's commander calls the situation serious, but not life-threatening. (AP Photo/NASA, Paolo Nespoli, File)
In this image provided by NASA astronaut Nicole Stott, Expedition 20 flight engineer, participates in the STS-128 mission's first session of extravehicular activity on the International Space Station Sept. 1, 2009. Two deployed radiators are visible behind Stott. The International Space Station has a radiator leak in its power system. The outpost's commander calls the situation serious, but not life-threatening. The six-member crew on Thursday May 9, 2013 noticed white flakes of ammonia leaking out of the station. (AP Photo/NASA)
CAPE CANAVERAL, Fla. (AP) ? Two astronauts took a hastily planned spacewalk Saturday to find and, possibly, fix a serious leak at the International Space Station.
Flakes of frozen ammonia coolant were spotted Thursday drifting from the long frame that holds the solar panels on the left side. Less than 48 hours later, Thomas Marshburn and Christopher Cassidy emerged from the orbiting lab to hunt for the leak. They were prepared to replace a pump, if necessary.
NASA said the leak, while significant, poses no safety threat. But managers wanted to deal with the trouble now, while it's fresh and before Marshburn returns to Earth in just a few days.
The space agency has never staged such a fast, impromptu spacewalk for a station crew. Even during the shuttle days, unplanned spacewalks were rare.
At the beginning of the spacewalk, neither astronaut spotted any flakes of ammonia or anything else amiss as they reached the spot in question and began an inspection.
"I see nothing off-nominal," Cassidy said. He noted some smudges, but nothing more.
The astronauts needed to take pictures of the equipment, but the connection to the camera's flash was not working and Marshburn had to wait until the space station reached the daylight side of Earth.
Flight controllers in Houston worked furiously to get ready for Saturday's operation, completing all the required preparation in under 48 hours. The astronauts trained for just such an emergency scenario before they rocketed into orbit; the repair job is among NASA's so-called Big 12.
This area on the space station is prone to leaks. The ammonia coursing through the plumbing is used to cool the space station's electronic equipment. There are eight of these power channels, and all seven others were operating normally. As a result, life for the six space station residents was pretty much unaffected, aside from the drama unfolding Saturday 255 miles above the planet.
NASA's space station program manager Mike Suffredini said it's a mystery as to why the leak erupted. One possibility is a micrometeorite strike. If there is nothing to suggest that the old pump is at fault, then the spacewalkers expect to leave it in place and go back inside as flight controllers figure out the next step.
Marshburn has been on the space station since December and is set to return to Earth late Monday. Cassidy is a new arrival, on board for just 1? months.
"Suddenly very busy," Marshburn said via Twitter on Friday.
By coincidence, the two performed a spacewalk at this troublesome spot before, during a shuttle visit in 2009.
___
Online:
NASA: http://www.nasa.gov/mission_pages/station/main/index.html
Associated Pressgluten free diet barry zito mac virus santorum drops out bby zimmerman website miami marlins
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.